Research Article An Investigation on the Properties of ...downloads.hindawi.com/journals/ijps/2014/326716.pdf · Li+ bonded ether group, free bonded ether, and hydrogen ether. However,

Research ArticleAn Investigation on the Properties of Palm-BasedPolyurethane Solid Polymer Electrolyte

Farah Nadia Daud1 Azizan Ahmad12 and Khairiah Haji Badri12

1 School of Chemical Sciences and Food Technology Faculty of Science and Technology Universiti Kebangsaan Malaysia43600 Bangi Selangor Darul Ehsan Malaysia

2 Polymer Research Center Faculty of Science and Technology Universiti Kebangsaan Malaysia 43600 BangiSelangor Darul Ehsan Malaysia

Correspondence should be addressed to Azizan Ahmad azizanukmmy

Received 30 May 2013 Revised 9 February 2014 Accepted 20 February 2014 Published 30 March 2014

Academic Editor Marek Cypryk

Copyright copy 2014 Farah Nadia Daud et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Palm-based polyurethane electrolyte was prepared via prepolymerization method between palm kernel oil polyol (PKO-p) and241015840-diphenylmethane diisocyanate (MDI) in acetone at room temperature with the presence of lithium trifluoromethanesulfonate(LiCF

3SO3)The effect of varying the concentration of LiCF

3SO3salt on the ionic conductivity chemical interaction and structural

and morphological properties of the polyurethane solid polymer electrolyte was investigated The produced film was analyzedusing electrochemical impedance spectroscopy (EIS) attenuated total reflection Fourier transform infrared (ATR-FTIR) X-raydiffraction (XRD) and scanning electron microscopy (SEM) The EIS result showed that the highest ionic conductivity was at 30wt LiCF

3SO3with a value of 16 times 10minus5 Ssdotcmminus1 Infrared analysis showed the interaction between lithium ions and amine group

(ndashNndashH) at (3600ndash3100 cmminus1) carbonyl group (ndashC=O) at (1750ndash1650 cmminus1) and ether group (ndashCndashOndashCndash) at (1150ndash1000 cmminus1) ofthe polyurethane forming polymer-salt complexes The XRD result proved that LiCF

3SO3salt completely dissociates within the

polyurethane film as no crystalline peaks of LiCF3SO3were observed The morphological study revealed that the films prepared

have a good homogeneity and compatibility as no phase separation occurred

1 Introduction

Since the discovery of ionic conductivity phenomenon insolid state by Faraday in the 1800s numerous studies havebeen conducted on polymer electrolytes pioneered by PeterWright and Michel Armand who had introduced the firstnew class of solid ionic conductors in the 1970s [1] Studiesshowed that liquid electrolyte has higher ionic conductivitycompared to other electrolyte systemsHowever it has severaldisadvantages namely leakage gas formation during oper-ation and difficulty in handling for portable applicationswhich has resulted in increasing studies conducted on solidpolymer electrolyte given its potential for applications insolid batteries electrochromic windows sensors fuel celland others [2]

However most of the current researches focus onthe production of petrochemical based polymers such as

polyethylene oxide (PEO) compared to polymers based onnatural resources Awareness of the importance of safe andenvironmental friendly sources of polymer has resulted inthe studies replacing the dependence on petrochemical basedpolymers conductors Moreover with the current price hikeof petroleum the use of raw materials based on naturalresources for industrial purposes also has increased Palmoil-based products have become one of the alternativesfor the production of polyols for polyurethane products[3]

Polyurethane is a copolymer that consists of urethanelinkages (ndashNHCOO) in its molecular structure It is typicallymade by the reaction of a polyester or polyether polyolwith diisocyanate As a block copolymer it has a uniquemultiphase structure consisting of soft segments and hardsegments that are suitable as matrix materials in polymerelectrolyte Studies carried out by Badri et al [4] described the

Hindawi Publishing CorporationInternational Journal of Polymer ScienceVolume 2014 Article ID 326716 5 pageshttpdxdoiorg1011552014326716

2 International Journal of Polymer Science

method of producing monoester polyol (PKO-p) from palmkernel oil (PKO)

One of the approaches to produce polyurethanes isthrough prepolymerization technique in the presence of asolvent This gives the advantage of lower isocyanate vaporlevels and heat reduction of the final reaction compared toa single step polymerization A single step polymerization ofpolyurethane gives off heat during formation of the urethanebonds and might cause shrinkage problem Meanwhileprepolymerization allows for partial heat dissipation prior tothe formation of polyurethane as discussed elsewhere [5ndash7]

In this research polyurethane was produced via pre-polymerization method between PKO-p and 2 41015840-diphenyl-methane diisocyanate (MDI) in acetone at room temperatureThe effect of different concentrations of LiCF

3SO3salt on

the ionic conductivity chemical interaction and structuraland morphological properties of the polyurethane solidpolymer electrolyte was investigated using electrochemicalimpedance spectroscopy (EIS) attenuated total reflectionFourier transform infrared (ATR-FTIR) X-ray diffraction(XRD) and scanning electron microscopy (SEM)

2 Experimental

21 Materials Palm kernel oil-based polyol (PKO-p) wasprepared as described by Badri et al [4] 241015840-diphen-ylmethane diisocyanate (MDI) was purchased from Cos-mopolyurethane (M) Sdn Bhd Port Klang Malaysia Ace-tone was supplied by Systerm Sdn Bhd Shah AlamMalaysia Polyethylene glycol (PEG) and lithium trifluor-omethanesulfonate (LiCF

3SO3) were purchased from Sigma-

Aldrich Sdn Bhd Kuala Lumpur Malaysia All materialswere used without further purification

22 Preparation of Prepolymerized Polyurethane (PU) Themethod used by Wong and Badri [5] was followed PKO-p and MDI were separately dissolved in acetone at roomtemperature to form urethane prepolymer The amount ofLiCF3SO3salt was varied at 5 to 30wt The LiCF

3SO3salt

was dissolved in the PKO-p and stirred via magnetic bar for30min The MDI was then added into the PKO-p drop-wiseand the mixture was stirred for another 5min and casted intoa Teflon plate The solvent was allowed to slowly evaporatein a fume hood at room temperature for 24 h The films wereyellow in color translucent and free standing

23 Measurements The ionic conductivity measurementswere carried out by EIS using a high frequency resonanceanalyzer (HFRA Solartron 1260 Schlumberger) with appliedfrequency ranging from01 to 106Hz at a perturbation voltageof 1000mV The disc-shaped sample of 16mm diameter wassandwiched between two stainless steel blocking electrodesThe ATR-IR spectrum was recorded by Perkin Elmer Spec-trum 2000 in the range of 4000 to 650 cmminus1 with a scanningresolution of 4 cmminus1 The analysis was conducted to study theinteraction between LiCF

3SO3salt and the functional groups

presence in polyurethane polymeric chain XRD model D-5000 Siemen was used to determine presence of crystalline

Table 1 The effect of LiCF3SO3 salt on the ionic conductivity of thepolymer electrolyte

LiCF3SO3 (wt) Ionic conductivity (120590) (Ssdotcmminus1)0 sim10minus12

5 18 times 10minus8

10 13 times 10minus7





or amorphous phase as a function of salt concentration Thedata was collected at diffraction angle 2120579 of 5∘ to 60∘ at therate of 004∘sdotsminus1 The morphologies of the cross-sectionedpolymer electrolytes were analyzed using SEM Philip modelXL30 at 1000x magnifications with 17 kV electron beam Thethickness of the film obtained ranged from 011 to 017mmThe whole analysis was conducted at room temperature

3 Results and Discussion

31 Ionic Conductivity In the complex impedance plot thereal quantityZ1015840 (x-axis) was plotted againstZ10158401015840 (y-axis) whichdisplayed the polymer electrolytes characteristics as an arcfollowed by linear spike that was a straight line inclinedto the real axis The bulk resistance (Rb) of the electrolytesystem was determined from an impedance plot where theionic conductivity (120590) was calculated from Rb that wasobtained from the intercept on the real axis (Z1015840) the filmthickness (l) and the contact area of the thin film (119860 =1205871199032= 120587(080 cm)2 = 201 cm2) according to the equation

120590 = [l(ARb)] [8 9] Table 1 shows the conductivity of PU-LiCF3SO3electrolyte at varying concentration of LiCF

3SO3

salt conducted at room temperature The ionic conductivityincreased with increasing concentration of LiCF

3SO3salt

The ionic conductivity increased threemagnitudes comparedto pristine PU with the addition of only 5wt LiCF

3SO3

(18 times 10minus8 Ssdotcmminus1) The highest conductivity was recordedat 30wt LiCF

3SO3with conductivity of 16 times 10minus5 Ssdotcmminus1

This increment was contributed by the number of conductingspecies in the electrolyte caused by ion dissociation ofLiCF3SO3 This occurred due to the presence of coordinating

atoms in the polymer host [10 11] The conducting speciesor free mobile ions present in the polymer may increase theamorphous structure of the polymer host through favorablefree volume thus it eases the ion migration [12 13] Theion transport phenomenon was further discussed in the IRspectroscopy analysis

32 IR Spectroscopy Analysis Previous studies [14ndash17] havereported the presence of strong hydrogen-bonding inter-action in poly(ether-urethane) that leads to changes inPU microstructure consisting of soft and hard segmentsThe nature of the interaction and coordination of Li+ andCF3SO3

minus ions transport within the PU chains was analyzedby mean of the IR spectrum [18] In the hard segment

International Journal of Polymer Science 3

30003200340036003800

Tran

smitt

ance

()

010

2030

Wavenumber (cmminus1)

PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3

Figure 1 The N-H peak of PU at 3290 cmminus1 shifted to the right asthe concentration of the lithium salt increased

the urethane groups have electrostatic charges at hydrogenoxygen and nitrogen atoms forming dipoles which attractanother atom of opposite chargeThemain functional groupsin the regions such as 3600ndash3100 cmminus1 (the hydrogen bondedNndashH stretching mode and the free NndashH stretch) 1750ndash1650 cmminus1 (the carbonyl symmetric stretching vibration oramide band) (ndashC=O) and 1150ndash1000 cmminus1 (the ndashCndashOndashCndashstretch) were identified to discern the effect of LiCF

3SO3

on the chemical interaction of the PU electrolyte Figure 1exhibited that the N-H peak of PU at 3290 cmminus1 shifted to ahigher wave number as the concentration of the lithium saltincreased indicating that free N-H was generated and therewas less hard-hard segment hydrogen bonds left [19 20]

Peak of ether group (ndashCndashOndashCndash) at 1017ndash1029 cmminus1(Figure 2) became intense while peak at 1105 cmminus1 becamealmost a plateau due to overlapping peaks contributed by theLi+ bonded ether group free bonded ether and hydrogenether

However Figure 3 indicated a reduction in intensity ofthe hydrogen bonded carbonyl group at 1707 cmminus1 as theconcentration of salt increased Meanwhile peak of thenonhydrogen bonded carbonyl urethane group at 1720 cmminus1shifted to a lower frequency due to the interaction withlithium ions From the observation conducted on the ATR-IRspectroscopy analysis it can be deduced that lithium salts hadinteracted with both the hard segments which were the NndashHand C=O and also the soft segment which was ndashCndashOndashCndash ofpolyurethane and affected the crystallinity of polyurethane asobserved in the XRD analysis [19]

33 X-Ray Diffraction Analysis (XRD) The X-ray diffractionanalysis is used to determine the structure complexationand crystallization of the polymer matrix The effect ofcomplexation of PU-LiCF

3SO3system was investigated by

performing XRD analysis where the appearance of the amor-phous region or the reduction of the crystalline region would

10001020104010601080110011201140

Tran

smitt

ance

T (

)

010

2030


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3

Figure 2 Peak of ether group (ndashCndashOndashCndash) at 1017ndash1029 cmminus1and1105 cmminus1 for the free bonded ether and hydrogen ether

1660168017001720174017601780

0

1020

30


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3

Tran

smitt

ance

T (

)

Figure 3 The hydrogen-bonded carbonyl group at 1707 cmminus1 andthe nonhydrogen bonded carbonyl urethane group at 1720 cmminus1

result in high ionic conductivity compared to the crystallineand semicrystalline region as reported by Sursquoait et al [21]The measurement was conducted in the range of 5∘ndash60∘at diffraction angle of 2120579 Figure 4 shows the XRD patternof pristine PU and the PU-LiCF

3SO3to study the change

of crystalline structure upon addition of different weight


10 20 30 40 50 60

Inte

nsity

(Cps

)

0

1000

2000

3000

PU1 + 0 LiTf

PU1 + 10 LiTf

PU1 + 20 LiTf

PU1 + 30 LiTf

minus1000

2120579 (deg)

Figure 4 XRD patterns of PU1 with varying amount of LiCF3SO3

percentages (10 20 and 30) of LiCF3SO3 From the

diffractogram we can observe that the pristine PU film wasa semicrystalline polymer with a broad hump at 20∘ andcrystalline peaks at 31∘ 52∘ and 53∘ As the salt additionincreased the crystalline peaks decreased and disappearedas 30wt of LiCF

3SO3was added into PU The hump

becomes broader and flatter proving that the PU becamemore amorphous upon the salt addition [22] In amorphousstate greater ionic diffusivity can occur as ions can movein the amorphous phase freely because of low energy bar-rier Besides the amorphous polymer exhibits more flexiblebackbone which can increase local chainmobility Hence thesegmental motions of the polymer will also increaseThis willthen improve the transportation property of the electrolytesystem [9]

34 Scanning Electron Microscopy (SEM) Figure 5 shows theSEM micrograph of the pristine PU film It exhibited a clearand smooth surface However the presence of LiCF

3SO3in

the PU film was obviously shown upon drying of the sampleHigher loading of the LiCF

3SO3gavemore distribution of the

LiCF3SO3salt on the PU film This was strongly supported

by the XRD analysis where there was a reduction in thecrystallinity of the sample Thus higher conductivity wasobserved The micrographs of the PU electrolytes at 1020 and 30wt showed the uniformly distributed sphericalgrains in the electrolyte system (Figures 6 7 and 8) Themore the appearance of the LiCF

3SO3salt on the PU film

the higher the conductivity increase

4 Conclusion

In this study palm-based polyurethane solid polymerelectrolyte was successfully prepared via prepolymeriza-tion method The highest conductivity obtained was 16times 10minus5 Ssdotcmminus1 at 30wt of LiCF

3SO3 FTIR spectroscopy

analysis confirmed that there was possible interaction thatoccurred between PU and lithium ions in the amine etherand carbonyl groupThe structural analysis recorded by XRD

Figure 5 SEM micrograph of pristine polyurethane

Figure 6 SEM micrograph of the PU film containing 10wtLiCF3SO3




showed the reduction of the PU crystalline phase at thehighest conductivity

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by School of Chemical Sci-ences and Food Technology as well as Polymer ResearchCenter Faculty of Science and Technology and UniversitiKebangsaan Malaysia It has been financially supported byMalaysia Ministry of Higher Education by research Grantno FRGS12011TKUKM0239 and Ministry of ScienceTechnology and Innovation by project no 03-01-02-SF0949

References

[1] M B Armand P G Bruce M Forsyth B Scrosati and WWieczorek Polymer Electrolytes Energy Materials John Wileyand Sons 2011

[2] S Rajendran M Sivakumar and R Subadevi ldquoLi-ion conduc-tion of plasticized PVA solid polymer electrolytes complexedwith various lithium saltsrdquo Solid State Ionics vol 167 no 3-4pp 335ndash339 2004

[3] T L Ooi A Salmiah A H Hazimah and Y J ChongldquoAn Overview of R and D in Palm Oil-Based Polyols andPolyurethane in MPOBrdquo A Bulletin of Palm Oil Developments2006

[4] K H Badri S H Ahmad and S Zakaria ldquoProduction of ahigh-functionality RBDpalmkernel oil-based polyester polyolrdquoJournal of Applied Polymer Science vol 81 no 2 pp 384ndash3892001

[5] C S Wong and K H Badri ldquoChemical analyses of palmkernel oil-based polyurethane prepolymerrdquo Material Sciencesand Application vol 3 pp 78ndash86 2012

[6] T S VelayuthamW H A Majid A B Ahmad G Y Kang andSNGan ldquoSynthesis and characterization of polyurethane coat-ings derived from polyols synthesized with glycerol phthalicanhydride and oleic acidrdquo Progress in Organic Coatings vol 66no 4 pp 367ndash371 2009

[7] S Li R Vatanparast and H Lemmetyinen ldquoCross-linkingkinetics and swelling behaviour of aliphatic polyurethanerdquoPolymer vol 41 no 15 pp 5571ndash5576 2000

[8] ldquoScanning electron microscoperdquo in Surface Analysis Studieson Polymer Electrolyte Membranes Using Scanning ElectronMicroscope and Atomic Force Microscope U Ulaganathan RNithya S Rajendran and V Kazmiruk Eds chapter 33 2012

[9] M Y A Rahman A Ahmad T K Lee Y Farina and HM Dahlan ldquoLiClO

4salt concentration effect on the properties

of PVC-modified low molecular weight LENR50-based solidpolymer electrolyterdquo Journal of Applied Polymer Science vol124 no 3 pp 2227ndash2233 2012

[10] A Ahmad M Y A Rahman S P Low and H Hamzah ldquoEffectof LiBF

4salt concentration on the properties of plasticized

MG49-TiO2based nanocomposite polymer electrolyterdquo ISRN

Materials Science vol 2011 Article ID 401280 7 pages 2011

[11] M S Sursquoait A Ahmad H Hamzah and M Y A RahmanldquoPreparation and characterization of PMMA-MG49-LiClO

4

solid polymeric electrolyterdquo Journal of Physics D AppliedPhysics vol 42 Article ID 055410 2009

[12] S Ramesh and G P Ang ldquoImpedance and FTIR studieson plasticized PMMA-LiN(CF

3SO2)2nanocomposite polymer

electrolytesrdquo Ionics vol 16 no 5 pp 465ndash473 2010[13] A Ahmad M Y A Rahman S P Low and H Hamzah ldquoEffect

of LiBF4salt concentration on the properties of plasticised


Materials Science vol 2011 Article ID 401280 7 pages 2011[14] W-C Chen H-H Chen T-C Wen M Digar and A

Gopalan ldquoMorphology and ionic conductivity of thermoplasticpolyurethane electrolytesrdquo Journal of Applied Polymer Sciencevol 91 no 2 pp 1154ndash1167 2004

[15] T-C Wen Y-J Wang T-T Cheng and C-H Yang ldquoThe effectof DMPA units on ionic conductivity of PEG-DMPA-IPDIwaterborne polyurethane as single-ion electrolytesrdquo Polymervol 40 no 14 pp 3979ndash3988 1999

[16] M Digar S L Hung H L Wang T C Wen and A GopalanldquoStudy of ionic conductivity and microstructure of a cross-linked polyurethane acrylate electrolyterdquo Polymer vol 43 no3 pp 681ndash691 2001

[17] S C Yoon and B D Ratner ldquoSurface and bulk structure of seg-mented poly(ether urethanes) with perfluoro chain extenders2 FTIR DSC and X-ray photoelectron spectroscopic studiesrdquoMacromolecules vol 21 no 8 pp 2392ndash2400 1988

[18] L Verdolotti S Colini G Porta and S Iannace ldquoEffects of theaddition of LiCl LiClO

4 and LiCF

3SO3salts on the chemical

structure density electrical and mechanical properties ofrigid polyurethane foam compositerdquo Polymer Engineering andScience vol 51 no 6 pp 1137ndash1144 2011

[19] S Wang S Jeung and K Min ldquoThe effects of anion structureof lithium salts on the properties of in-situ polymerized ther-moplastic polyurethane electrolytesrdquo Polymer vol 51 no 13 pp2864ndash2871 2010

[20] T-C Wen Y-L Du and M Digar ldquoCompositional effecton the morphology and ionic conductivity of thermoplasticpolyurethane based electrolytesrdquo European Polymer Journalvol 38 no 5 pp 1039ndash1048 2002

[21] M S Sursquoait A Ahmad H Hamzah and M Y A Rah-man ldquoEffect of lithium salt concentrations on blended49 poly(methyl methacrylate) grafted natural rubber andpoly(methyl methacrylate) based solid polymer electrolyterdquoElectrochimica Acta vol 57 no 1 pp 123ndash131 2011

[22] S Ramesh and A K Arof ldquoStructural thermal and elec-trochemical cell characteristics of poly(vinyl chloride)-basedpolymer electrolytesrdquo Journal of Power Sources vol 99 no 1-2pp 41ndash47 2001

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Polymer ScienceInternational Journal of



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CompositesJournal of

NanoparticlesJournal of



International Journal of

Biomaterials


NanoscienceJournal of

TextilesHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of

CrystallographyJournal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014


CoatingsJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Smart Materials Research



MetallurgyJournal of


BioMed Research International

MaterialsJournal of


Nano

materials


Journal ofNanomaterials


method of producing monoester polyol (PKO-p) from palmkernel oil (PKO)

One of the approaches to produce polyurethanes isthrough prepolymerization technique in the presence of asolvent This gives the advantage of lower isocyanate vaporlevels and heat reduction of the final reaction compared toa single step polymerization A single step polymerization ofpolyurethane gives off heat during formation of the urethanebonds and might cause shrinkage problem Meanwhileprepolymerization allows for partial heat dissipation prior tothe formation of polyurethane as discussed elsewhere [5ndash7]

In this research polyurethane was produced via pre-polymerization method between PKO-p and 2 41015840-diphenyl-methane diisocyanate (MDI) in acetone at room temperatureThe effect of different concentrations of LiCF

3SO3salt on

the ionic conductivity chemical interaction and structuraland morphological properties of the polyurethane solidpolymer electrolyte was investigated using electrochemicalimpedance spectroscopy (EIS) attenuated total reflectionFourier transform infrared (ATR-FTIR) X-ray diffraction(XRD) and scanning electron microscopy (SEM)

2 Experimental

21 Materials Palm kernel oil-based polyol (PKO-p) wasprepared as described by Badri et al [4] 241015840-diphen-ylmethane diisocyanate (MDI) was purchased from Cos-mopolyurethane (M) Sdn Bhd Port Klang Malaysia Ace-tone was supplied by Systerm Sdn Bhd Shah AlamMalaysia Polyethylene glycol (PEG) and lithium trifluor-omethanesulfonate (LiCF

3SO3) were purchased from Sigma-

Aldrich Sdn Bhd Kuala Lumpur Malaysia All materialswere used without further purification

22 Preparation of Prepolymerized Polyurethane (PU) Themethod used by Wong and Badri [5] was followed PKO-p and MDI were separately dissolved in acetone at roomtemperature to form urethane prepolymer The amount ofLiCF3SO3salt was varied at 5 to 30wt The LiCF

3SO3salt

was dissolved in the PKO-p and stirred via magnetic bar for30min The MDI was then added into the PKO-p drop-wiseand the mixture was stirred for another 5min and casted intoa Teflon plate The solvent was allowed to slowly evaporatein a fume hood at room temperature for 24 h The films wereyellow in color translucent and free standing

23 Measurements The ionic conductivity measurementswere carried out by EIS using a high frequency resonanceanalyzer (HFRA Solartron 1260 Schlumberger) with appliedfrequency ranging from01 to 106Hz at a perturbation voltageof 1000mV The disc-shaped sample of 16mm diameter wassandwiched between two stainless steel blocking electrodesThe ATR-IR spectrum was recorded by Perkin Elmer Spec-trum 2000 in the range of 4000 to 650 cmminus1 with a scanningresolution of 4 cmminus1 The analysis was conducted to study theinteraction between LiCF

3SO3salt and the functional groups

presence in polyurethane polymeric chain XRD model D-5000 Siemen was used to determine presence of crystalline

Table 1 The effect of LiCF3SO3 salt on the ionic conductivity of thepolymer electrolyte

LiCF3SO3 (wt) Ionic conductivity (120590) (Ssdotcmminus1)0 sim10minus12

5 18 times 10minus8






or amorphous phase as a function of salt concentration Thedata was collected at diffraction angle 2120579 of 5∘ to 60∘ at therate of 004∘sdotsminus1 The morphologies of the cross-sectionedpolymer electrolytes were analyzed using SEM Philip modelXL30 at 1000x magnifications with 17 kV electron beam Thethickness of the film obtained ranged from 011 to 017mmThe whole analysis was conducted at room temperature

3 Results and Discussion

31 Ionic Conductivity In the complex impedance plot thereal quantityZ1015840 (x-axis) was plotted againstZ10158401015840 (y-axis) whichdisplayed the polymer electrolytes characteristics as an arcfollowed by linear spike that was a straight line inclinedto the real axis The bulk resistance (Rb) of the electrolytesystem was determined from an impedance plot where theionic conductivity (120590) was calculated from Rb that wasobtained from the intercept on the real axis (Z1015840) the filmthickness (l) and the contact area of the thin film (119860 =1205871199032= 120587(080 cm)2 = 201 cm2) according to the equation

120590 = [l(ARb)] [8 9] Table 1 shows the conductivity of PU-LiCF3SO3electrolyte at varying concentration of LiCF

3SO3

salt conducted at room temperature The ionic conductivityincreased with increasing concentration of LiCF

3SO3salt

The ionic conductivity increased threemagnitudes comparedto pristine PU with the addition of only 5wt LiCF

3SO3

(18 times 10minus8 Ssdotcmminus1) The highest conductivity was recordedat 30wt LiCF

3SO3with conductivity of 16 times 10minus5 Ssdotcmminus1

This increment was contributed by the number of conductingspecies in the electrolyte caused by ion dissociation ofLiCF3SO3 This occurred due to the presence of coordinating

atoms in the polymer host [10 11] The conducting speciesor free mobile ions present in the polymer may increase theamorphous structure of the polymer host through favorablefree volume thus it eases the ion migration [12 13] Theion transport phenomenon was further discussed in the IRspectroscopy analysis

32 IR Spectroscopy Analysis Previous studies [14ndash17] havereported the presence of strong hydrogen-bonding inter-action in poly(ether-urethane) that leads to changes inPU microstructure consisting of soft and hard segmentsThe nature of the interaction and coordination of Li+ andCF3SO3

minus ions transport within the PU chains was analyzedby mean of the IR spectrum [18] In the hard segment


30003200340036003800

Tran

smitt

ance

()

010

2030


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3



3SO3







10001020104010601080110011201140

Tran

smitt

ance

T (

)

010

2030


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3


1660168017001720174017601780

0

1020

30


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3

Tran

smitt

ance

T (

)






10 20 30 40 50 60

Inte

nsity

(Cps

)

0

1000

2000

3000

PU1 + 0 LiTf

PU1 + 10 LiTf

PU1 + 20 LiTf

PU1 + 30 LiTf

minus1000

2120579 (deg)







3SO3in







4 Conclusion












Acknowledgments


References

















4













4 and LiCF














CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




30003200340036003800

Tran

smitt

ance

()

010

2030


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3



3SO3







10001020104010601080110011201140

Tran

smitt

ance

T (

)

010

2030


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3


1660168017001720174017601780

0

1020

30


PU1 + 0 LiCF3SO3

PU1 + 10 LiCF3SO3

PU1 + 20 LiCF3SO3

PU1 + 30 LiCF3SO3

Tran

smitt

ance

T (

)






10 20 30 40 50 60

Inte

nsity

(Cps

)

0

1000

2000

3000

PU1 + 0 LiTf

PU1 + 10 LiTf

PU1 + 20 LiTf

PU1 + 30 LiTf

minus1000

2120579 (deg)







3SO3in







4 Conclusion












Acknowledgments


References

















4













4 and LiCF














CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials




10 20 30 40 50 60

Inte

nsity

(Cps

)

0

1000

2000

3000

PU1 + 0 LiTf

PU1 + 10 LiTf

PU1 + 20 LiTf

PU1 + 30 LiTf

minus1000

2120579 (deg)







3SO3in







4 Conclusion












Acknowledgments


References

















4













4 and LiCF














CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials







Acknowledgments


References

















4













4 and LiCF














CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials










CeramicsJournal of







Biomaterials




Journal of


Journal of





CoatingsJournal of

Advances in








MaterialsJournal of


Nano

materials



Documents

Research Article An Investigation on the Properties of ...downloads.hindawi.com/journals/ijps/2014/326716.pdf · Li+ bonded ether group, free bonded ether, and hydrogen ether. However,